Field of the Invention and Description of the Prior Art
This invention relates to improved business forms and manifold assemblies and it particularly relates to multiple ply business forms of the type having a pair of outer plies and a removable inner ply, the business forms being initially interconnected as a manifold assembly.
Correspondence stationery systems or mailer constructions are business form assemblies that have been known in the art for many years. These systems comprise manifold assemblies produced on high speed equipment of a known type and generally include at least a pair of outer plies, with the outer plies commonly forming a mailing envelope. The interior of the mailing envelope is stuffed with one or more plies of selected inserts, such as return envelopes, questionnaires, invoices, promotional material, and the like. In these assemblies, it is common to include either plies of carbon paper or carbonless copy paper. It is quite common to have certain material printed on the outer ply to be selectively imprinted on the internal ply by the carbon paper or carbonless copy paper. In carrying this out, however, it is important for the intermediate ply or plies to remain fixed during imprinting and handling because otherwise the printed characters on the inner plies would become illegible if the intermediate ply moves relative to the outer ply.
In addition to remaining fixed during handling and imprinting, it is important for the intermediate ply to be readily removable from association with the other plies by opening the outer plies in any suitable manner, such as by "bursting" the form.
It is seen, therefore, that there are at least two important considerations required in designing correspondence stationery of the type described herein. A problem created by these two requirements is that each requirement conflicts with the other; that is, one requirement calls for the insert material to be secure within the outer plies so as not to move during manufacture, handling, and imprinting while the other requirement calls for the intermediate ply or plies to be readily separable or removable from association with the outer plies.
Examples of prior art manifold assemblies include those shown in Steidinger U.S. Pat. No. 3,104,799, Steidinger U.S. Pat. No. 3,339,827, Van Malderghem U.S. Pat. No. 3,554,438, Allen U.S. Pat. No. 4,010,889, and Peshke U.S. Pat. No. 4,108,352.